West syndrome

(Hypsarrhythmia, flexor spasms)

Estimated incidence of 1/3,000 births. Association of infantile spasms, a typical intercritical EEG (hypsarythmia) and mental retardation. The syndrome is caused in about 80 % of cases by a brain abnormality: neonatal hypoxia, sequelae of infection, isolated malformation  or associated with other abnormalities (Bourneville tuberous sclerosis, or phenylcetonuria for example). In about 10 % of cases, no cause or lesion is found: this is called cryptogenic West syndrome. The prognosis is better for cryptogenic forms of West syndrome.

West syndrome is a form of epilepsy (15-50 % of infant epilepsy) that usually occurs in the small infant (starting classically around 5 months of age, but cases have been described that started up to 5 years) by:



The spasms tend to decrease or disappear before 5 years of age but relapses are observed.


Treatment: vigabatrine is the first choice; in case of failure, hydrocortisone or ACTH treatments are associated. Other antiepileptics or a ketogenic diet are associated in case of treatment-resistant epilepsy. Epilepsy surgery is used only for localized brain malformations.


Anesthetic implications:

treatment-resistant epilepsy, mental retardation.

In case of a ketogenic  diet:



preoperative
period

-        take advice from the neuropediatrician: efficacy of the diet, which treatment in case of seizure, side effects (urinary lithiases ?)

-        evaluation: RBC, WC, platelets, electrolytes, urea, creatinine, Ca, Mg, albumin and prealbumin (nutrition). SGOT and SGPT levels are often moderately elevated

-        avoid prolonged fasting: clear unsweetened fluids allowed

-        avoid sweetened fluids in the premedication

-        avoid IV administration of carbohydrates containing IV fluids

-        check glycemia at induction: ideally 50-80 mg/dL


anesthesia

-        propofol: OK for induction but avoid TIVA: source of glycerol, risk of PRIS and pancreatitis

-        fluids: 0.9 % NaCl (risk of worsening metabolic acidosis) or Ringer lactate (but lactate promotes gluconeogenesis)

-        avoid corticosteroids: dexamethasone?

-        avoid carbohydrate-containing medications (glucose, mannitol, glycerol) if possible

-        the transfusion of labile blood products is a hidden intake of carbohydrates

-        in case of hypoglycemia, correct with low doses of glucose (0.25g/kg)

-        monitor glycemia, pH, electrolytes, NaHCO3


postoperative

-        resume the ketogenic diet as soon as possible

-        check ketone bodies (urine): between 40 and 160 mg/dL or at least 2 ++


Ketogenic diet: perianesthetic recommendations


References : 

-         Niesen AD, Jacob AK, Aho LE, Botten EJ, Nase KE, Nelson JM, Kopp SL. 
Perioperative seizures in patients with a history of seizure disorder. 
Anesth Analg 2010; 111:729-35.

-           McNeely JK. 
Perioperative management of a paediatric patient on the ketogenic diet. 
Pediatr Anesth 2000; 10:103-6.

-                Baumeister FA, Oberhoffer R, Liebhaber GM. 
Fatal propofol infusion syndrome in association with ketogenic diet. 
Neuropaediatrics 2004; 35:250-2.

-        Conover ZR, Talai A, Klockau KS, Ing RJ, Chaterjee D.
Perioperative management of children on ketogenic dietary therapies.
Anesth Analg 2020 ; 131 :1872-82.


Updated: November 2020